django创建项目时，urls.py报错：No module named 'index.urls'

django创建音乐网站项目时，urls.py写入代码后，pycharm一直报错： No module named 'index.urls'

用idle运行时候就报错：
Requested setting INSTALLED_APPS, but settings are not configured. You must either define the environment variable DJANGO_SETTINGS_MODULE or call settings.configure() before accessing settings.

创建过程中只修改了urls.py 和setting.py 文件
代码如下：
[b]urls.py[/b]

from django.contrib import admin

from django.urls import path, include

from django.conf.urls import url

from django.views import static

from django.conf import settings

urlpatterns = [

path('admin/', admin.site.urls),
path('', include('index.urls')),
path('ranking.html', include('ranking.urls')),
path('play/', include('play.urls')),
path('comment/', include('comment.urls')),
path('search/', include('search.urls')),
path('user/', include('user.urls')),

]

[b]settings.py[/b]
（部分代码）
INSTALLED_APPS = [

'django.contrib.admin',
'django.contrib.auth',
'django.contrib.contenttypes',
'django.contrib.sessions',
'django.contrib.messages',
'django.contrib.staticfiles',
'index',
'ranking',
'user',
'play',
'search',
'comment',

]

MIDDLEWARE = [

'django.middleware.security.SecurityMiddleware',
'django.contrib.sessions.middleware.SessionMiddleware',
# 使用中文
'django.middleware.locale.LocaleMiddleware',
'django.middleware.common.CommonMiddleware',
'django.middleware.csrf.CsrfViewMiddleware',
'django.contrib.auth.middleware.AuthenticationMiddleware',
'django.contrib.messages.middleware.MessageMiddleware',
'django.middleware.clickjacking.XFrameOptionsMiddleware',

]

ROOT_URLCONF = 'music.urls'

TEMPLATES = [

{
    'BACKEND': 'django.template.backends.django.DjangoTemplates',
    'DIRS': [
        os.path.join(BASE_DIR, 'templates'),
        os.path.join(BASE_DIR, 'index/templates'),
        os.path.join(BASE_DIR, 'ranking/templates'),
        os.path.join(BASE_DIR, 'user/templates'),
        os.path.join(BASE_DIR, 'play/templates'),
        os.path.join(BASE_DIR, 'comment/templates'),
    ],
    'APP_DIRS': True,
    'OPTIONS': {
        'context_processors': [
            'django.template.context_processors.debug',
            'django.template.context_processors.request',
            'django.contrib.auth.context_processors.auth',
            'django.contrib.messages.context_processors.messages',
        ],
    },
},

]

WSGI_APPLICATION = 'music.wsgi.application'

DATABASES = {

'default': {
    'ENGINE': 'django.db.backends.mysql',
    'NAME': 'music_db',
    'USER': 'root',
    'PASSWORD': '1234',
    'HOST': '127.0.0.1',
    'POST': '3306',
}

}

请问这种情况该如何处理呢？求指点

已解决：在app下添加urls.py就可以了